scholarly journals Determination of Residues of Eight Synthetic Pyrethroids in Tobacco by Capillary Gas Chromatography

Author(s):  
BS Dattilo ◽  
S Gallo ◽  
G Lionetti

AbstractA method was developed for the simultaneous determination of the residues of the following eight synthetic pyrethroids and their isomers in tobacco: tetramethrin, permethrin, cyfluthrin, cypermethrin, alfamethrin, flucythrinate, fluvalinate and deltamethrin. The pesticides were extracted from ground tobacco by means of acetone:water 9:1 for 5 hours. The extract was diluted with water and partitioned into n-hexane. The organic phase was concentrated to about 1 ml and then purified by a Florisil-SPE column. The gas-chromatographic analyses were run with a gas-chromatograph Carlo Erba Series Mega HRGC 5300 equipped with a capillary column (stationary phase OV-1 - 0.10-0.15 µm film thickness, 25 m long) and a 63Ni electron-capture detector. Two different injection ports were used: split-splitless and cold split-splitless, working both with isothermal and programmed temperatures. Both the limit of detection and the limit of determination were estimated for each compound. Recoveries from fortified samples at level of 1 µgKg-1 are reported.

1984 ◽  
Vol 30 (10) ◽  
pp. 1672-1674 ◽  
Author(s):  
N B Smith

Abstract In this method for detection and quantification of volatile alcohols by capillary gas chromatography, the serum sample is deproteinized, then directly injected into the gas chromatograph with 1-propanol as the internal standard. The capillary column is a 30-m bonded methylsilicone-coated, fused-silica column. With helium as the carrier gas, the injector inlet is set at a split ratio of 1/30 and the average linear velocity in the column is 25 cm/s. Injector and flame-ionization detector temperatures are 280 degrees C, oven temperature 35 degrees C. Chromatography time is less than 3 min.


1980 ◽  
Vol 63 (5) ◽  
pp. 952-958
Author(s):  
Louis G M T Tuinstra ◽  
Wim A Traag ◽  
Henk J Keukens

Abstract A method is described for determining individual polychlorinated biphenyls (PCBs) in milkfat at the ppb level. Extraction and major cleanup are done simultaneously by saponification of the milkfat. After final cleanup on basic alumina, the concentrated extract is injected under splitless conditions on a capillary column coated with CPSil 7 stationary phase. The recovery of several individual PCBs from milkfat at a level of 25 ppb is better than 80%. The reproducibility for duplicates analyzed on several days showed standard deviations from 0.2 to 0.9 ppb for 19 individual chlorinated biphenyls. Some preliminary results for 165 samples of milkfat are reported.


1987 ◽  
Vol 70 (5) ◽  
pp. 912-915 ◽  
Author(s):  
Randall L Smith ◽  
Darryl M Sullivan ◽  
Earl F Richter

Abstract A positive bias in the gas chromatographic (GC) analysis of butter for β-sitosterol was discovered when attempting to confirm values by gas chromatography/mass spectrometry (GC/MS). The source of the problem was traced to an interfering material that was not effectively separated by packed column GC. Because capillary columns are known to provide superior separation, they were substituted for packed columns in the assay, and instrument parameters were modified accordingly. A compound with a similar retention time, identified by GC/MS as lanosterol, was separated from β-sitosterol by the capillary column. The capillary column technique was applied to over 300 butter samples. The results indicate that the method can accurately quantitate β-sitosterol in butter with no known interferences. The limit of detection for this method is 1 mg/100 g. Recoveries at a level of 3 mg/100 g averaged 98% with a coefficient of variation of 3.45%


1986 ◽  
Vol 69 (6) ◽  
pp. 976-980
Author(s):  
Richard A Niemann

Abstract Surrogate spiking the sample with 1000 parts per trillion (pptr) 1,3,7,8-tetrachlorodibenzo-p-dioxin (1378-TCDD) has doubled analytical throughput in determining toxic 2378-TCDD (analyte) at the low partper- trillion level in fish, using multicolumn high resolution liquid chromatographic cleanup before quantitation by capillary gas chromatography with electron capture detection. The 1378- and 2378-TCDD were recovered equally and were well separated by the capillary column so that the earlier-eluting surrogate did not interfere with the quantitation of levels of analyte many-fold lower. Matrix interference contributed <1 % bias in surrogate quantitation. Using surrogate recovery to correct for analyte losses during analysis, accuracy averaged (n = 7) 105% in determining 18 or 45 pptr 2378-TCDD added to fish without detectable bioincurred analyte. Analyses of selected fish with bioincurred 2378-TCDD gave results comparable to earlier work where recovery correction required a second analysis of sample fortified with analyte. With surrogate fortification, repeatability of determination (n = 3 or 4) improved markedly to <5% relative standard deviation at 37-46 pptr.


2000 ◽  
Vol 83 (5) ◽  
pp. 1225-1228 ◽  
Author(s):  
Angeliki Tsigouri ◽  
Urania Menkissoglu-Spiroudi ◽  
Andreas T Thrasyvoulou ◽  
Grigorios C Diamantidis

Abstract A simple, rapid, and accurate method is described for the determination of residual fluvalinate in beeswax. The procedure consists of partitioning on a disposable column of diatomaceous earth (Extrelut®), followed by chromatographic cleanup on a Florisil cartridge. The final extract is analyzed by capillary gas chromatography with electron-capture detection (GC–ECD). Briefly, wax samples were dissolved in n-hexane, and the solutions were sonicated and transferred to Extrelut columns. The fluvalinate was extracted with acetonitrile, and a portion of the extract was cleaned up on a Florisil cartridge. The fluvalinate was eluted with diethyl ether–n-hexane (1 + 1) and directly determined by GC–ECD. Recoveries from wax samples spiked at 5 fortification levels (100–1500 μg/kg) ranged from 77.4 to 87.3%, with coefficients of variation of 5.12–8.31%. The overall recovery of the method was 81.4 ± 3.2%, and the limit of determination was 100 μg/kg.


2008 ◽  
Vol 6 (2) ◽  
pp. 229-236
Author(s):  
M. Awan

AbstractA single step derivatisation for the determination of putrescine and cadaverine by gas chromatography using trifluoroacetylacetone (TFAA) in methanol or ethanol was studied and optimised. The derivatives were analysed by an iontrap gas chromatograph-mass spectrometer (GC-MS) operating with electron impact ionisation with selective ion storage (EI-SIS) mode. The optimised mole ratios for TFAA/putrescine and TFAA/cadaverine reactions were 5/1 and 5.8/1 respectively with a reaction time of 15 minutes at 95oC. The retention times for the derivatised putrescine and cadaverine were 11.3 and 12.2 minutes respectively using the capillary column, CP-Sil 8CB; 30 m length x 0.25 mm i.d. x 0.25 mm film. The correlation coefficients (R2) of calibration curves for putrescine and cadaverine were 0.991 and 0.990 respectively over a concentration range of 100 ng cm−3 to 1500 ng cm−3. The method developed was found to be simple (single-stage derivatisation), rapid (15 minutes derivatisation & 14 minutes GC/MS run) and accurate (putrescine and cadaverine recoveries 94.8%–97.7%).


2021 ◽  
Vol 17 ◽  
Author(s):  
Fatang Yang ◽  
Xiaoyun Duan ◽  
Zhen Wang ◽  
Yuming Dong

Aims: To establish a rapid and simultaneous determination of multiple effective ingredients in anti-cold drugs. Background: Anti-cold drugs are stock medicines at home, and most anti-cold formulations are compound preparations. Although the active ingredients of compound preparations have significant effects on the treatment of colds, the excessive dosage or long-term use can produce a series of adverse reactions including dependence, liver and kidney function damage, digestive system reaction, blood system damage. Now, there are many mature methods for analyzing the active ingredients of anti-cold drugs. However, these methods may have shortcomings such as a long analysis time or a small number of analysis components. Objective: Establish a gas chromatography-flame ionization detector method for the simultaneous determination of six active ingredients including acetaminophen, dextromethorphan hydrobromide, pseudoephedrine hydrochloride, chlorpheniramine maleate, diphenhydramine hydrochloride, and caffeine in anti-cold drugs. Method: After the standard was accurately weighed, dissolved in ethanol, filtered by 0.22 μm membrane and ultrasonically degassed, the gas chromatograph was used for detection. After the actual sample was removed from the coating, ground and crushed, accurately weighed, dissolved in ethanol, filtered by 0.22 μm membrane and ultrasonically degassed, the gas chromatograph was used for detection. Result: The six components can be completely separated within 7.0min. This method has good sensitivity, precision, accuracy and recovery rate. Under the optimum testing conditions, the limit of detection was 0.360-2.50μg/mL, the limit of quantification was 1.20-8.30μg/mL. The calibration curves showed good linearity (R2≥0.9932) over the investigated concentration range between 1.20 and 400μg/mL. The recoveries were 89.2% to 109.2%. The RSD of intra-day precision was less than 1.0%. The RSD of inter-day precision was less than 3.2%. The established method was used to determine the ingredients of three anti-cold drugs on the market, and the results showed that the method can accurately determine the ingredients. Conclusion: The method can quickly and simultaneously determine multiple active ingredients in anti-cold medicines. Compared with the published methods in literatures, the proposed method has the advantages of fast, the number of analysis componentswide application range, convenience, low cost, etc. It provides a reference method for quality control of active ingredients of anti-cold drugs.


2011 ◽  
Vol 382 ◽  
pp. 477-480 ◽  
Author(s):  
Tao Liu ◽  
Lin Xia Zhang ◽  
Li Quan Sun ◽  
Ai Qin Luo

One geminal dicationic ionic liquid (IL) was synthesized and coated in column as stationary phase for capillary gas chromatography (CGC). In this study, two times imidazolium cations were reacted with 1,4-bis(chloromethyl)-benzene and then the anions exchanged to bis(trifluoromethylsulfonyl)-imide (NTf2-). The new ILs was coated statically in capillary column. The outcome of the stationary phase was evaluated by separating Grobs mixture, n-alkanes mixture, alcohols mixture and aromatic position isomers mixture such as xylene, nitrotoluene, dichlorobenzene and cresol. The results indicated that new IL possessed good column coating properties and chromatographic separation abilities.


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